Convert between miles and kilometres in both directions. One mile equals exactly 1.609344 kilometres.
1 mile in kilometres, and a 26.2-mile marathon in km.
1 mile = 1.6093 km exactly (internationally defined). The conversion works both ways.
A mile is an imperial unit; the kilometre is metric. They're related by a fixed, internationally agreed factor, so conversion is exact (unlike, say, temperature).
km = miles × 1.609344 · miles = km × 0.621371
Is the conversion exact?
The factor 1.609344 is exact by international agreement, so mile↔km conversion has no rounding error beyond your display.
What's a marathon in km?
26.219 miles, defined as exactly 42.195 km.
Why do US road signs use miles?
The US and a few other countries retain imperial units; most of the world uses kilometres.